Mobil 1 says "easily" between 7,500 and 10,000 miiles. ->link

Then again...what do they know? They only made the stuff.

 

Did my first oil change today with 4,400 miles on the clock, while the oil didn't look to bad, you could see some of the gunk the oil filter caught. (I was only at 42% on my oil life monitor).
My advice would be to do your first oil change probably within the first 2k miles to catch all the break in gunk, then switching to, a longer regular mileage oil change routine.
After looking at my filter today I wish I would have done my first oil change at 2k miles.
Take it for what its worth.

 

You have to keep in mind though that our cars use a filter cartridge as opposed to the typical spin-on filter. You can actually see the filter element, where on the typical car, you wouldn't unless you cut open the can. So, what you were seeing could be perfectly normal. That also means it was doing it's job and none of that stuff was recirculated back into the engine.

 

^^^Yep I know, still would recommend doing it early on for the first oil change.